Tension and take-up device for sewing-machines



(No Model.) 2 Sheets-Sheet 1.

J. W. BLODGETT. TENSION AND TAKE-UP DEVICE FOR SEWING MACHINES.

No. 246,591. Patented Sept. 6,1881.

(No Model.) 2 Sheets --Sheet 2. J. W. BLODGETT.

TENSIONAND TAKE-UP DEVICE FOR SEWING MACHINES.

No. 246,591. Patented Sept. 6,- 1881.

Wiifiesgesk- Invent 0T.

UNiTED STATES PATENT OFFICE.

JOHN W. BLODGETT, OF CHICAGO, ILLINOIS.

TENSION AND TAKE-UP DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 246,591, datedSeptember 6, 1881.

Application filed March 19, 1881. (No model.)

To all whom it may concern:

Be it known that I, JOHN W. BLODGETT, residing at Chicago, in the countyof Cook and State of Illinois, and a citizen of the United States, haveinvented new anduseful Improvements in Tension and Take-Up Devices forSewing-Machines, of which the following is a full description, referencebeing bad to the accompanying drawings, in which Figure 1 is a sideelevation of a sewing-machine embodying my invention; Fig. 2, a top orplan view of the arm of the same; Figs. 3, 4, and 5, details of thetake-up device; Figs. 6 and 7, details of the socket or collar by meansof which the tension arm or spring is held in position and its pressureregulated.

A proper tension on the thread and the taking up of the slack threadconstitute two of the essential featuresin the successful working of asewing-machine, and in practice it has been found that the tensionshould be one that can be regulated or changed so as to adapt it toditl'erent conditions and requirements of the work and to the amount andquality of the thread, and that the takeup should be automatic in itsoperation, and perform its work so as to prevent any tangling orknotting of the thread, and at the same time be adjustable so as toaccommodate itself to the amount of the slack in the thread.

To construct devices that will accomplish these desired endssuccessfully and perform their respective works in an efficient andreliable manner, and so as not to injure and break the thread orinterfere with the operation of the machine, and which can be easily andquickly changed or regulated so as to adapt them to the varyingconditions and requirements of the work and the thread, is the ob- 0ject of this invention; and it consists in providing a spring orspring-arm, secured at one end to a collar or socket, which can beraised or lowered on its spindle or arbor and be ro- --tated thereon, soas to cause the free end of provided with an adjustable set-collarlocated on the tube or casing for limiting the action of the spring andcausing its movement to correspond to the amount of slack in the thread.

1n the drawings, A represents the tension arm, made of spring-steel orother suitable material, and of the requisite flexibility, so that whenits f1 ee end is hearing on the spool or thread it will exert thenecessary pressure to prevent the thread from bein g unwound, except asrequired for use.

B is a set-collar or socket having a central circular opening adapted toreceive an arbor or spindle, to which the collar or socket can be firmlysecured and held in any desired position by means ofa set-screw, b, orother suitable device, so thatit can be raised or lowered to bring it inthe proper position for support ing the spring A properly. In thissocket or collar B is a transverse slot or opening, a, to

receive the end of the tension-arm A, and by turning the socket orcollar on its arbor or spindle the angle at which this slot to stands inreference to a straightline parallel with the arbors or spindles for thespool and the socket B can be made greater orless, so as to cause thefree end of thetension-arm A to bear with a greater or less force on thethread, and thereby vary the amount or degree of tension.

0 is a spindle or arbor for the socket or collar B. Its lower end isfirmly secured, in the form of construction shown, to the ordinary arm,I, ofthe machine which supports the head H for the presser-ioot andneedle-bars Grand H.

D is an ordinary spool for thread.

E is a spindle or arbor for the spool. Its lower end, as shown, isfirmly secured to the sewing-machine arm forward of the spindle or arborO, and its diameter is such as to allow the spool to be placed thereonand rotate free- 1y. The position and location of the spindles or arborson the machine may be varied to adapt them to machines of differentconstructions and bring the tension device and spool in the properrelation to each other.

By means of the spring or spring-arm A and the adj ustable and rotatingsocket or 001- lar B it will, be seen that any desired tension can begiven by simply turning the socket or collar on its arbor, so as tocause the free end of the spring-arm or tension-arm to bear with IOCmore or less force, and that all that is necessary to be done in orderto produce this result is to loosen the set-screw ot' the collar, turnthe collar in the required direction, and then tighten the set-screw. Toincrease the tension the socket or collar B is turned so as tocause theend ofthe slot or opening a which is toward the spool to be carriedinward or toward a line drawn through the centers of the arbors G and D.To decreasethe tension a reverse movement is given to the socket orcollar B. By thus changing the line of direction of the slot a anyrequired degree of tension can be applied to the thread.

Fis a casing or tube, secured atits lower end to the upper end of theneedle-bar G so as to move therewith, and having its upper end left openso as to permit of the insertion of a coilspring, d. ()n opposite sidesof this casing or tube F and in line with each other are slits c, topermit of the passage of the thread transversely through the tube orcasing and over the upper end ofthecoil-spring d,- and in order tosupport the thread properly a cap, 0, having an extension, 0, which fitsthe interior of the spring is provided, on which cap 6 the thread rests,and, as shown, the cap is prevented from being thrown out bythe recoilof the spring by a set-screw, h, or in any other suitable manner. Aroundthe casing or tube F is located an adjustable set-collar, j", which canbe adjusted up or down on the tube, and when in the desired position canbe held therein by a set-screw, g, or other suitable device. Thisset-collarflimits the descending movement of the coilspring by reason ofthe thread coming in contact there with, so as to have the descent ofthe spring correspond to the slack in the thread.

The operation will be readily understood. The thread, passing over thecoil-spring, as it is drawn by the descent of the needle will cause thecoil spring to contract to the same extent, and as the needle ascendsthe spring will return to its normal condition, and will, of course,take up any slack there may be in the thread, and by means of theset-collar the contraction of the spring can be made to correspond withthe descent of the needle, and the recoil of the spring will be to thesame extent.

By means of this device the slack thread will all be taken up in anetficient manner, and the tension-arm prevents any unwinding of thethread from the spool, except as required, so

that kinking and knotting of the thread will not take place, and nointerference will arise with the operation of the machine.

In Fig. 1 a button-hole attachment is shown, but as the same is made thesubjectmatter of another application of even date herewith it need nothere be described.

I do not claim a flat spring arranged to press upon the spool of threadand having its tension adjusted by a set-screw bearing against thespring between its point of attachment to the machine and the spool ofthread; neither do I broadly claim a sliding cap arranged on theneedle-bar and supported by a coiled spring, the cap having an eyethrough which the thread passes on its way to the needle.

What I claim as new, and desire to secure by Letters Patent, is-

1. In a tension device for sewing-machines, the combination ot' thefixed cylindrical arbor O, the collar 15, provided with the transverseslot a and set-screw Zr, and arranged to be rotated and adjustedvertically on the spindle to change the position or angle of the slot,and the flat spring A, having one end secured in the transverse slot andits free end arranged to bear on the spool. of thread, substantially asdescribed, whereby the pressure of the spring on the spool can beadjusted by turning the slotted collar on its axis, all as and for thepurpose described.

2. The tube F, secured to the needle-bar and provided with twocoincident vertical slots, 0, extending to the upper end of said tube,in combination with a coiled spring, at, arranged within the tube, andthe thread-rest bearing on the spring and closely fitting and slidingwithin the slotted tube, all substantially as and for the purposedescribed.

3. The tube F, secured to the needle-bar and having the two verticalcoincident slots 00,

the coil-spring d, arranged within the tube, the

cap piece a, closely fitting and sliding within the tube, and the collarf, arranged to slide upon the exteriorofthe tube, and provided with asetscrew, g, for adjusting and locking the collar in position toregulate the descent of the coil-spring, all substantially as and forthe purpose described.

JOHN W. BLODGETT.

W'itnesses:

O. W. BOND, 13. A. PRICE.

